Improvement of velopharyngeal closure (contact of the soft palate with the throat walls to prevent air escapage to the external environment through the nasal passages) and speech intelligibility by a palatal exercise consisting of pressure stimulation during a simultaneous phonatory act by the patient has been accomplished by the use of an inflatable oral prosthesis positioned opposite the soft palate. Reference is here made to U.S. Pat. No. 3,447,534 which sets forth in some great degree these concepts. The exercise, however, has been administered by hand squeezing a bulb operated by the patient, and leaves much to be desired in this type of treatment.